Electric cathode type furnace

Electric boiler for private home heating

Electric boilers are especially relevant in rural areas and country houses that do not have access to gas mains. In addition, the installation of such equipment does not require approval of the installation project with specialized services, which is costly both financially and psychologically.

Electric boiler for heating private houses

Distinctive features of electric boilers are compact and easy to install. With a basic knowledge of electrical engineering and a minimum set of tools, the unit of induction or electrode type can be made and installed independently.

This review examines the device, principle of operation and design features of electrode heating units, provides feedback from users who have evaluated the pros and cons of this equipment in practice. A separate section is devoted to a brief description of the most popular models.

What is an electrode boiler

The principle of operation of the unit is clearly demonstrated by the known to many boilers of two blades and four matches. When such a device is connected to the mains, heating 1 l of water to 100 0 C takes a few minutes.

This intensity of heating of the electrode boiler is achieved through the phenomenon of electrolysis. The essence of the process is that between two electrodes immersed in a solution of liquid electrolyte, when an external voltage source is connected, the directional movement of charged particles begins. Ions with a positive charge move to the cathode, while particles with a negative charge are attracted to the anode.

If an AC voltage of 50 Hz is applied to the electrodes from the household electrical grid, the polarity is reversed 50 times during one second, which causes a periodic reversal of the direction of movement of the ions. Due to the increased resistance of the aqueous medium and internal friction, kinetic energy is converted into thermal energy, which causes intensive heating of the electrolyte solution.

Since water in centralized supply systems has little in common with pure (H₂O) and is a solution of salts of potassium, calcium, magnesium and other elements, it may well be considered an electrolyte. Direct heating of the electrolyte (without contact with the surface of the heating element or housing) is called primary.

The fundamental difference between electrode boilers and other electrical units is that the coolant is heated without contact with the heating element.

It should also be noted that the performance of the unit is directly related to the chemical composition of the coolant.

Design and operating principle of the electrode boiler

Since the principle of operation of the unit is not particularly complicated, the design of the units is extremely simple.

The electrode boiler includes:

1. The body;
2. The terminal for connecting the neutral wire;
3. Base;
4. Electrode;
5. Terminal for connecting the phase wire;
6. Inlet spigot;
7. Outlet spigot;
8. Casing;
9. Terminal for connection of grounding or neutral grounding.

In most designs the role of the second electrode is played by the device body 1 , connected to the neutral wire through the terminal 2 .

The vessel on one side is hermetically sealed by the base 3, in which the central electrode 4 is fixed. Voltage supply to the rod is carried out by the phase wire through the terminal 5 .

The supply of the coolant is carried out through the inlet 6 , located in the lower part of the unit. The heated coolant enters the heating mains through the outlet spigot 7 , usually located in the upper cover of the product. For the installation of fittings both nipples have threaded ends.

The outer casing 8 has a special terminal 9 for connecting the grounding wire and serves as additional protection against electric shock. In addition, the shape and polyamide coating of the casing can provide an attractive appearance of the entire installation.

To increase the efficiency of the heating system, a circulation pump is installed in front of the inlet, which provides intensive passage of fluid through the working cavity of the device.

If you need more than 10 kW power to achieve the desired result, it is advisable to use an electrode boiler connected to a three-phase electrical network.

The principle of operation of the three-electrode unit does not differ from that of a conventional boiler, the difference is the number of rods and their placement. Each electrode is connected to a separate phase through special terminals at the bottom of the unit. The rods are located at the vertices of a regular equilateral triangle inscribed in the circumference of the operating cylinder. To ground the device, a terminal on the housing is used.

Since during operation the electrodes can be destroyed, the design of the unit provides for their rapid replacement. To do this, it is necessary to:

1. Drain the coolant from the heating system;
2. Disconnect the bottom cover;
3. Replace the destroyed electrodes;
4. Replace the bottom cover and check for leaks;
5. Fill the line with liquid electrolyte;
6. Resume power supply.

The advantage of electrode installations is that there is no destruction of boiler parts in the absence of coolant in the system.

Control systems

Since the design of the boiler itself does not provide any control elements, regulation is carried out using external control systems.

The simplest unit consists of a temperature sensor which is installed in front of the inlet pipe and which disconnects the power supply when the set temperature is reached. More precise regulation is performed by means of two temperature sensors located at the inlet and outlet.

The cost of the automatic control system is the most significant component of the price of the electrode boiler, which can vary in a fairly wide range.

Pros and cons of electrode boilers for heating

Despite the contradictory reviews of owners, it is impossible not to note the obvious advantages of electrode units:

• The design of the boiler provides compactness and ease of connection.
• Small overall dimensions allow the use of units as additional or backup heat generators, included independently of the main as needed.
• Boiler installation does not require design and approval.
• If the coolant leaks, the unit will not fail and can continue to operate immediately after troubleshooting.
• Electric boilers are not susceptible to voltage fluctuations in the power grid.
• No harmful emissions, and no powerful electromagnetic fields.

The list of advantages is really weighty, but along with them, some objective disadvantages should be noted:

• The use of electrode devices is not appropriate in the presence of radiators made of steel or cast iron in the heating system. Effective operation can only provide bimetallic radiators and high quality radiators made of aluminum, which significantly increases the cost of the heating circuit.
• High requirements for the quality and chemical properties of the coolant. The fluid used must provide optimal conditions for electrolysis.
• Installation of the electrode boiler is only possible in a closed circuit, which entails additional costs for a sealed expansion vessel, emergency pressure relief valve and air vent.
• The maximum temperature of the heating medium must not exceed 85 0 C.

Having carefully analyzed all the disadvantages of the unit, you can come to the conclusion that they are all related to the quality and chemical properties of the coolant.

Overview and prices of the best brands of electrode boilers

Currently, the most popular are several manufacturers of electrode heating devices.

Products of the domestic production company “Galan” are in demand not only in the Russian Federation, but also throughout the CIS. Reliable and economical units “Geyser”, “Volcano” and “Ochag” are characterized by compact size, long service life and attractive design. For heating a private house most often used modification “Ochag – 6”, which has the following technical characteristics:

• Starting current – 15 A;
• Rated power of the installation – 6 kW;
• Weight without coolant – 1.7 kg;
• Body height – 320 mm.

The advantages of the electrode boiler are its affordable price, easy installation and maintenance. For effective long term work it is desirable to install a voltage regulator and use as a coolant special fluids.

The price of the unit is 4500 rubles.

Ukrainian company offers electrode boilers, the body of which is made of seamless steel pipe with a wall thickness of 4-5 mm. The product line consists of heaters rated from 2 to 12 kW, working on a domestic power supply and three-phase models up to 125 kW. The highest demand is for devices generating from 3 to 6 kW. Specifications:

• Nominal power rating of 3 to 6 kW;
• The maximum heated area – 120 m 2 ;
• The length of the body cylinder – 185 mm;
• Weight – 7 kg.

The delivery set includes the control system and circulation pump. Price electrode boiler – 7500 rubles.

Products of this Russian brand automatically takes into account the state of the electrolyte in the heating circuit and adjusts the operation of the installation. Like many other manufacturers, the company produces devices for single-phase electricity with a rated capacity of 2 to 10 kW and for three-phase network, designed for 35 kW. Feedback from buyers of electrode devices indicate that the most popular model is “Beril – 9”, which has the following technical characteristics:

• Power of the unit – 9 kW;
• Connection – three-phase;
• The maximum heated area – 250 m 2 .

The product is easy to install in the heating circuit, and the control system provides the ability to adjust the power in the range from 2 to 9 kW. The average price of the unit is 8,500 rubles.

Protherm Scat 24 KR 13

The electrode boiler has proven itself as a safe, reliable and efficient device. The power of the installation is 24 kW, the basic equipment includes an expansion tank of 7 liters and a circulation pump. The obvious advantages of the boiler include:

• A wide temperature range (can be adjusted from 30 to 85 0 C);
• The product is equipped with safety systems against overheating and soft start;
• There is a four-stage power control.

The minimum price of the unit is 43 thousand rubles.

Below are reviews of the owners of electrode systems, who have assessed the advantages and disadvantages of such systems in practice.

Electrode boilers for heating a private house reviews of owners

Since user reviews play a significant role in the choice of the boiler, here are some of them.

• After reading the reviews of the electrode installation “Galan Ochag 3”, testifying to its low power consumption, the quality of automation and affordable cost decided to use this miracle of technology. The result is quite satisfactory, the apartment is warm and comfortable. As advice, I can say the following: be sure to install a circulating pump and you will be satisfied. Mykola, Odessa.
• The area of our summer house about 200 m 2, and here with the gas is somehow not the fate of the time. In winter the situation saves the boiler Obriy-15. At first feared the bill for electricity, but nothing supernatural in the receipt did not find, even a little less than with the old storage boiler. After two years of operation, as they say, there are no major shortcomings. Dmitry, Krasnodar .
• For two-storey house with a total living area of 140 m2 decided to use electrode boiler “Luch”, the capacity of 15 kW. Installation did not cause any difficulties, I had only to play with the preparation of the coolant, but here, too, the instruction helped. Heat is produced quite enough, and the energy consumption, compared to the boiler with 150 liters is slightly reduced. Andriy, Dnepropetrovsk.
• Installing the electrode boiler ION-6 in the house has completely changed my views on the heating in general, I never knew that everything can be so simple and compact. The area of the house is about 65 m2, ceiling height – 2.8 m and all enough of this device, which is difficult to call a boiler, so compact. As for electricity consumption, for a month winds up 400-450 kW, in my opinion, quite acceptable. Fedor Mikhailovich, Voronezh.

Electric boiler with its own hands drawings

Before we proceed to the manufacture, it should be borne in mind that the lion’s share of the price electrode installation is not for the heater itself, and the electronic control system, the pump, which provides circulation of coolant and other components, to make which at home is unlikely to succeed. Well, for those who still decided to try their hand, below is a step by step guide.

1. At one end of the pipe screwed coupling, which will play the role of the output pipe.
2. At the other end is screwed on a tee, which provides the supply of coolant.
3. A plug is made of durable textolite or other dielectric material to secure the electrode in the center. To make the electrode itself, you can use a steel rod with a diameter of 10-12 mm. After the rod is installed, the plug is screwed into the tee together with the electrode.
4. Two M8 bolts are welded to the pipe, which will serve as terminals for the neutral conductor and grounding.
5. The device is connected to the heating circuit via the socket and the free end of the tee.

Particular attention should be paid to the sealing of threaded joints and grounding device.

Modern electrode heating boilers have a simple design, reliability and long service life and are quite competitive with solid fuel and gas boilers. Using electricity avoids both the tedious preparation of firewood or coal, and the device chimneys.

Is it worth using electrode boilers for heating a private home

If everything is very clear with the widespread THEN models of electric boilers, then the understanding of the principle of operation, advantages and disadvantages of electrode heating boilers is not present for everyone. This is due to exaggerated claims of marketers, claiming incredible savings and, conversely, with feedback from owners who are convinced that this is not quite true.

In fact, the electrode boilers – it’s just conventional electric boilers, somewhat different principle, compact size and lower cost. But should they be used to heat your home and how true all of the existing opinions, let’s find out by examining the principle of operation and differences from the standard THENE electric boilers.

What are the electrode heating boilers

Electrode boilers are characterized by compact size, low-power single-phase models barely exceed the diameter of the heating system lines and do not require space around themselves, so they can be installed absolutely anywhere. But keep in mind that they are just a heat exchanger, in contrast to the TEN models in the monoblock case requires the separate purchase of the expansion tank, circulating pump, safety groups and other elements of the heating system.

Design and principle of operation

Boilers action is based on direct heating by means of electrolysis. In the body at a certain distance from each other are electrodes: cathodes, attracting when you apply a direct current positively charged water ions, and anodes, attracting negatively charged ions. But when alternating current is applied to the electrodes, they change polarity 50 times per second (the standard current frequency is 50 Hz), which causes the water ions to move continuously. Due to the high resistance of the medium, the kinetic energy of the moving ions is converted into thermal energy and the coolant is rapidly heated.

In the technical literature electrode boilers are also called electric boilers of direct heating, because the coolant is heated directly by passing current through it, and not by heating elements, which then heats the water.

On the one hand, such a principle of heating does not involve the formation of scale and the efficiency of ion electric boilers remains constant throughout life, while the efficiency of TEN models due to the scale formation when using as a coolant hard water over time decreases to 90 or even 80% (from the original 99%). On the other hand exposure to electric current increases the process of corrosion of all metal elements of the water circuit of the heating system.

For the operation of electrode boilers requires an undistilled and unfiltered coolant, which will act as an electrolyte. This can be ordinary tap water, propylene glycol or ethylene glycol. Almost all manufacturers of ionic electric boilers produce their own coolants and recommend using them (there is often a catch, because when you use a different coolant warranty loses, it is written in the passport of most models).

The use of distilled water, antifreeze or oil as a coolant is unacceptable.

Is it worth using them for heating a private house: let’s examine the known claims and misconceptions

• Electrode boiler is much easier and cheaper to install, since there is no need to organize the chimney and ventilation. In addition, its installation does not require approval.

This is true, but any electric boiler does not require a separate room for the boiler room, a special coating of walls, the organization of the chimney, supply and exhaust ventilation. The process of organizing the heating system with a boiler of ion type is really more simple, but not as simple as when using TEHN analogues, which already have in their bodies all the necessary nodes of the heating system (it is enough to connect only the flow and return).

Regarding the agreement, it all depends on the power. Any electric boilers with capacity over 10 kW require mandatory coordination with the services of Energonadzor. It is also important to understand that any electric boilers with a capacity above 6 kW must be connected to a three-phase power grid.

• Electric boilers have a higher efficiency, they are economical and consume 30-50% less electricity.

The efficiency of all modern electric boilers is over 99%, so such statements are just a marketing ploy or comparison with very old models, which are at least a few years off the market.

However, there is some truth in the statement, because due to the scale formation when using hard water as the coolant, the efficiency of TEN models over time decreases to 90 or 80%: to heat the coolant through a layer of scale takes more time and energy costs. The efficiency of ionic boilers remains stable for a long time.

Also the efficiency is seriously affected by the functionality of the automation. Automatics of ionic models is more simple and inferior to the THERM, where in models of the middle price segment and above there are energy-saving night modes, the ability to program the operation mode for a week ahead, etc. The problem can be solved by a room thermo regulator which costs 2 000-4 000 thousand rubles, but again this is additional cost levelling the main advantage of electrode boilers – low cost.

• Reliability and service life of electrode models is higher.

With competent, proper use, this is partly true, because the electrode boilers have the simplest possible device and any failure in the first 12-15 years of operation – a rarity.

At the same time, the only vulnerable part of TEN models is the heating element – TEN itself. If low-quality coolant is used, it should be replaced after 3-5 years, when using a prepared, purified and softened coolant – up to 8-10 years.

• Electric ion type boilers are safer.

In an emergency situation, this is indeed true and is justified by the principle of operation, because if the coolant leaks or power outage, the electrodes simply stop working. When power is supplied, they resume operation again without human intervention. TEN models in the absence of protection against overheating will not stop working when the coolant leaks, leading to destruction.

But the fact is that today, even many budget TEN electrical boilers have overheat protection, freeze prevention mode, protection against blocking the circulation pump. Therefore, this is an extremely controversial statement.

Efficiency and selection criteria for energy-saving electric heating boilers

Most electrode models cost between 4-9 thousand rubles, while the cost of heating elements – from 19 to 29 thousand for the most common models of the average price segment.

The low price of ion-type boilers is indeed a significant advantage, but often overestimated by the buyer. Keep in mind that to organize the system will have to separately buy an expansion tank, safety group, circulating pump and other components already available in the body of models with a tubular electric heater. And this is another 5-10 thousand rubles, to achieve greater comfort and economy you also need a functional electronic thermostat – another 2-4 thousand rubles.

Difficulties in operation

1. Competent operation according to requirements implies using of a quality coolant with a balanced chemical composition and all qualities of the electrolyte. Manufacturers recommend using fluids specially prepared for this purpose, with good ionization, sufficient heat capacity and anti-corrosion properties.Pouring ordinary tap water into the heating system is possible, but it usually leads to lower efficiency, rapid corrosion of all metal lines of the heating system. In addition, over time, any coolant loses its properties and requires replacement after 3-4 years, which also causes additional trouble and expense.
2. As we have already mentioned, the impact of electric current on ferrous metals and stainless steel significantly accelerates the corrosion process, which reduces the resource of the heating system. Therefore, in conjunction with electrode boilers it is generally not recommended to install steel or cast iron radiators – only aluminum or bimetallic. Otherwise, the life of radiators is reduced literally several times.
3. Phases of the electrical network are connected to the electrodes and the zero is connected to the body of the electric boiler, so you must always be a reliable all-round grounding and the installation of RCD is not recommended. If the grounding is of poor quality, dangerous potential can appear on pipes and radiators. In addition, it is necessary to make sure the quality of wiring in the house, because the equipment of high power creates a serious load on the power grid, causing voltage fluctuations. However, this is not a feature of ionic electric boilers, but in general any electrical equipment with a capacity of 4-6 kW.

To summarize: if you are not ready for additional work on the installation and peculiarities of ekuspluattsii electrode boilers, it is better to pay 20-30% of the cost and choose a TEN electrical boiler, which we recommend you do. Today they occupy about 90% of the market of electric boilers. But with a competent approach, there is a choice in favor of ionic boilers, the advantages and disadvantages are summarized below.

Reviews of household electric ion type boilers: advantages and disadvantages

Advantages

Disadvantages

The best known manufacturers and models: characteristics and prices

Galan

The most common Russian manufacturer of electrode boilers. It has the widest model range and power options: from low-power 2-3 kW models for heating small rooms to powerful 36 kW ionic boilers. Electric boilers are characterized by one of the most budget prices, fast heating, noiseless operation. Of the disadvantages – step regulation of power and expensive, recommended by the manufacturer, coolant (about 2,200 rubles per 20 liters).

The model range is represented not only by compact “Ochag”, “Geyser” and “Vulcan”, but also by monoblock “Galax”, in the body of which the expansion tank, circulation pump, safety valve, air vent and pressure gauge are already installed.

Cost: 4,000-13,000 rubles for compact models and 29,000-30,000 for monoblock models.

Another Russian manufacturer, the abbreviation stands for “Energy Saving Heating Units”.

The lineup is represented by electric boilers with capacity from 1 to 36 kW. Electrode EBOs are characterized by durability (the manufacturer claims a lifetime of 30 years) and operation from normal tap water. Disadvantages are mediocre automation, higher prices and mediocre availability, since the manufacturer is represented in the smallest part of the heating equipment market stores.

Cost: 4 600-15 000 rub.

Beril

Well-known Latvian manufacturer SIA “BERIL”. Despite the higher cost, electrode boilers Beril are one of the best for heating a private home, because high reliability, build quality and most importantly – multifunctional economical automation. There is a smooth regulation of power, several economical modes of operation, the ability to connect external temperature sensors or GSM-module, statistics of electricity consumption.

There are also protection against overheating and a mode of prevention of freezing, characteristic for TEN models.

Cost: 4 450-25 000 rubles.

Koterm

Another Russian manufacturer of heating equipment. The most successful model is considered Koterm “Dachnik M”, which features the most compact size, build quality and reliability, fast heating of the coolant. The known disadvantages – it is mediocre automation with only 3-stage power control and limited functionality, as well as the need to use a proprietary coolant only Koterm Eco.